1. Technical Field of the Invention
The present invention relates to a high-voltage electrical component unit for vehicles that supplies electric power to, for example, a motor for driving a vehicle.
Priority is claimed on Japanese Patent Application No. 2008-299283, filed Nov. 25, 2008, the content of which is incorporated herein by reference.
2. Background Art
Hybrid vehicles and fuel cell vehicles have a high-voltage battery (i.e., a high-voltage electrical storage device) mounted thereon as a power supply for driving vehicles in addition to a low-voltage battery as a power supply for auxiliary machines.
Electric power in the high-voltage battery relays battery protection circuits, such as a contactor and a fuse, and is output to a motor for driving a vehicle via an inverter-based power driven unit (PDU). The electric power is partially stepped down by a DC-DC converter and is charged in the low-voltage battery.
A high-voltage battery (hereinafter, referred to as an “electrical storage device”) is usually assembled integrally with both a power control block on which the PDU and the DC-DC converter are mounted and a power distribution block on which a contactor or other components are mounted. The electrical storage device is mounted on a vehicle as a high-voltage electrical component unit.
A high-voltage electrical component unit has been proposed in which a power distribution block is assembled integrally with an electrical storage device and a power control block is assembled to the power distribution block at a side opposite to the electrical storage device (for example, see Japanese Unexamined Patent Application, First Publication No. 2005-153827).
In this high-voltage electrical component unit, a locking claw is provided in the power distribution block at a side of the electrical storage device. The locking claw is latched to a groove formed in the electrical storage device for temporary fastening. In this state, the power distribution block and the electrical storage device are finally fastened to each other. The locking claw in the power distribution block is disposed at a lower side when the unit is assembled to a vehicle. In particular, when the power distribution block is fastened to the electrical storage device, both of these components are first turned upside down. In this state, the locking claw located at an upper side is latched to the groove formed on the electrical storage device. Then, the power distribution block and the electrical storage device are finally fastened to each other with, for example, bolts. Disposing the power distribution block and the electrical storage device upside down during assembling and mounting is due to followings. Heavy components, such as the contactor and switches, on the power distribution block are disposed at an upper side when the unit is mounted on a vehicle. Therefore, if the power distribution block and the electrical storage device are temporarily fastened to each other with the locking claw being engaged to the groove without being turned upside down, it is difficult to keep these components aligned with each other (i.e., the power distribution block collapses easily). That is, disposing these components upside down for temporary fastening of the power distribution block and the electrical storage device helps keeping these components in a stable temporarily fastening state with their own weight.
As another approach, a high-voltage electrical component unit has been proposed in which a power control block is assembled on an electrical storage device when the unit is mounted on a vehicle and a power distribution block is mounted across both side portions of the electrical storage device and the power control block (see Japanese Unexamined Patent Application, First Publication No. 2008-62780).
In this latter high-voltage electrical component unit, however, since the electrical storage device, which is a heavy component, is disposed below the power control block, when the electrical storage device and the high-voltage electrical component block are turned upside down along with the power distribution block during assembling as in the former high-voltage electrical component unit, the entire weight of the electrical storage device is applied to the power control block. This phenomenon is unfavorable from the viewpoint of protection of the high-voltage electrical component unit (the power control block).
Accordingly, in the latter high-voltage electrical component unit, an assembly block, which is configured by assembling the electrical storage device and the power control block together, and the power distribution block are assembled together without being turned upside down. In this case, however, it is difficult to keep the power distribution block aligned with the assembly block in a temporarily fastened state by only the locking claw of the power distribution block engaged to the groove formed in the electrical storage device. Especially in the latter high-voltage electrical component unit, since the electrical storage device and the power control block are stacked vertically to increase height thereof, the power distribution block assembled thereto may easily collapse during temporary fastening because the position of the center of gravity of the power distribution block becomes high.